est ignition on a 1989 4.3 liter cobra.

[rolmops]

I bought a 4.3 longblock from M.Motorz and I put a new starter a rebuilt carb a new pump and a new alternator . Basically a new engine. So I want to go from the old points ignition to a delco est ignition just like on my 4 cylinder mercruiser where it works great. My problem is that I cannot find a place on that 4.3 liter block to install the coil. Where should I install the coil? I considered to just put it on the transom very well grounded, but I'm afraid that it will overheat over there. Is there a place on the block where it fits? I tried to put it on the intake manifold but the distance between the bolts is too long. Ay other ideas? Thank you, Rolmops

 

[Scott06]

I bought a 4.3 longblock from M.Motorz and I put a new starter a rebuilt carb a new pump and a new alternator . Basically a new engine. So I want to go from the old points ignition to a delco est ignition just like on my 4 cylinder mercruiser where it works great. My problem is that I cannot find a place on that 4.3 liter block to install the coil. Where should I install the coil? I considered to just put it on the transom very well grounded, but I'm afraid that it will overheat over there. Is there a place on the block where it fits? I tried to put it on the intake manifold but the distance between the bolts is too long. Ay other ideas? Thank you, Rolmops

Why willit over heat on the transom? Wont be any difference in temp on transom vs mounted to engine .
if you look at the pics here looks like they mount the coil to back of cylinder head https://www.michiganmotorz.com/5-7l-vortec-marine-silver-package-315-hp-1967-current-replacement

 

[rolmops]

Thank you for your answer.
The reason I worry about overheating on the transom is the wood which acts as an insulator while the engine block although hotter than the transom still acts as a heatsink.
You really did help me with that picture. I realize that they probably used some angle iron to make it stand up, which is something I had not thought about

 

[Scott06]

The reason I worry about overheating on the transom is the wood which acts as an insulator while the engine block although hotter than the transom still acts as a heatsink.

dont over think it, either location will work fine As long as your wires are long enough.
i think MM just bolted it to the cylinder head . Volvo used the est on 4.3 s they may have a bracket that mounts the coil to back of engine or exhaust

 

[Scott Danforth]

You're overthinking it

Mount the coil anywhere you want

I would mount to the back of the head myself

 

[rolmops]

I think that my problem is solved. I looked on the MM website and came across a Delco EST bracket with a bracket for 4.3 liter engines. The one they originally sent me was for the 3 liter engine. I contacted them and They promised to send me the proper bracket asap. Now I'm waiting to get it so I can see whether it will work.
Thank you all for your help.

 

[rolmops]

The bracket arrived and it was not what I expected to be. It is an enlarged version of the metal piece that when bolted onto the block, allows you to hook a chain into a large hole and remove the block. There are two holes drilled into it on each end. One end to bolt it onto the block and the other end ,under the chain hole, to bolt the coil onto. It is probably a good place for the coil. I just hope that it does not get in the way of anything. I'll keep you guys posted.
I just realized that when I started posting on this site in 2002 I barely new the difference between the front and the rear of an outboard and now I have rebuilt several engines, restored 4 boats and currently work on the fifth. All of this with the generous help of so many good people like you.
Big kudos are in place for I-boats.

 

[Scott Danforth]

FWIW .... I put 125000 miles on a vehicle with the coil Zip-tied to a bolt sticking out the back of one of the heads.

Did the same on the SBC in the rogue. For the BBC, I made 316 Stainless version of the P-clamps. https://www.mcmaster.com/content/p-clamps/material~stainless-steel

 

[rolmops]

I found a place for the coil on the block, the power steering cooling setup is installed and now comes the wiring. Because I changed from points to the Delco EST system the wiring has to go a bit different. So far I removed the resistor wiring because the new coil needs the full 12 volts instead of 10. Now I wonder where to hook the switched 12 volt power supply. Should I stick with the esc on the alternator where the resistor wire was connected or is it a better idea to go like the 3 liter OH model which used the est coil and just hook it up to the closest switched 12 volt? Also, the original coil had a switched wire running from the coil back to the starter soilenoid. Should I just remove that? Or should I remove this from the EST coil and hook it to the 12 volt switched wire and keep it attached to the starter solenoid that way? I just do not have enough experience on the wiring front and because of that I need some good advice here.
I do have the OMC service manual, but because I am changing things it is not as helpful with the wiring as I would like it to be.
As always, your help and opinion is highly appreciated.
Thank you, Cornelis

 

[Scott06]

I found a place for the coil on the block, the power steering cooling setup is installed and now comes the wiring. Because I changed from points to the Delco EST system the wiring has to go a bit different. So far I removed the resistor wiring because the new coil needs the full 12 volts instead of 10. Now I wonder where to hook the switched 12 volt power supply. Should I stick with the esc on the alternator where the resistor wire was connected or is it a better idea to go like the 3 liter OH model which used the est coil and just hook it up to the closest switched 12 volt? Also, the original coil had a switched wire running from the coil back to the starter soilenoid. Should I just remove that? Or should I remove this from the EST coil and hook it to the 12 volt switched wire and keep it attached to the starter solenoid that way? I just do not have enough experience on the wiring front and because of that I need some good advice here.
I do have the OMC service manual, but because I am changing things it is not as helpful with the wiring as I would like it to be.
As always, your help and opinion is highly appreciated.
Thank you, Cornelis

You need a way to get 12 v when key is in start position and 12v when key is in run position. Don't have a wiring diagram but I suspect you will need the wire coming off the starter solenoid to get 12 v to + side of coil during cranking, and take 12v from upstream of where resistance wire was getting it (ESC on alternator- just needs to have 12 v in run. These two parallel paths will both supply to positive side of coil.

Do you have a shift cut out on yours that will need to be wired as well?

Do you have the wiring diagram and install instructions that come from Delco ?

 

[Lou C]

This is why l kept the points on mine; the choices were old school points, Petronix or Delco EST. I know points well having learned them in my 60s & 70s cars, Petronix has mixed reviews, Delco is probably the best. If you have the original OMC ESA module it will have to be changed to one that works with electronic ignition. These are available and sold by CDI electronics. I have one of theirs on mine & it works with either points or electronic. The original OMC ones do not as far as I know. If you figure this out please post your wiring changes because I’d consider the EST when I repower.

 

[rolmops]

You need a way to get 12 v when key is in start position and 12v when key is in run position. Don't have a wiring diagram but I suspect you will need the wire coming off the starter solenoid to get 12 v to + side of coil during cranking, and take 12v from upstream of where resistance wire was getting it (ESC on alternator- just needs to have 12 v in run. These two parallel paths will both supply to positive side of coil.

Do you have a shift cut out on yours that will need to be wired as well?

Do you have the wiring diagram and install instructions that come from Delco ?

Thank you for that advise. I'll go that way. I plan to do the shift cutout the mercruiser way as advised by Don. I do have the Delco instructions and wiring diagram for the 3 liter 4 cylinder mercruiser. I will see if I can find the instructions for the 4.3 liter Cobra

 

[Lou C]

I actually prefer the OMC ESA because it does not stall the engine as the simpler Merc can if you shift too slowly. Properly set up OMC’s is a better if more complex system. When you actuate the ESA it drops your idle from 600 rpm to 450. Mine has never stalled when shifting.

 

[Scott06]

Thank you for that advise. I'll go that way. I plan to do the shift cutout the mercruiser way as advised by Don. I do have the Delco instructions and wiring diagram for the 3 liter 4 cylinder mercruiser. I will see if I can find the instructions for the 4.3 liter Cobra

the instructions are here - is generic for all models ... https://marineengines4less.com/images/companies/1/EST Ignition Instructions - ME4L.pdf?1431462059320

of course these are generic so your mileage may vary

 

[rolmops]

There is one thing that I fail to understand. Near the alternator there is a 4 inch long round tube with roughly a one inch diameter. Its plus side is hooked into the purple wire on the harness and the negative grounds onto the block. It says "Sea ranger" I have no idea what purpose it serves. ( the cursive print is by accident) Anybody have an idea?

 

[Scott06]

There is one thing that I fail to understand. Near the alternator there is a 4 inch long round tube with roughly a one inch diameter. Its plus side is hooked into the purple wire on the harness and the negative grounds onto the block. It says "Sea ranger" I have no idea what purpose it serves. ( the cursive print is by accident) Anybody have an idea?

a picture may help

 

[Lou C]

Don’t think that’s OE! Nothing like that on my 1988 4.3

 

[rolmops]

I unwrapped the insulation around the wires and found out that this thing is hooked into the + orange wire that goes from the alternator to the battery and the other wire coming out goes to a ground. It is definitely after market but I am at a loss as to what is is for. Maybe a diode?

 

[bruceb58]

How are you planning on getting the shift interrupter ESA working?

 

[rolmops]

How are you planning on getting the shift interrupter ESA working?

For now I plan to completely bypass the ESA system and wire it exactly as a mercruiser. This means that I will connect a +wire to the shift interrupter while the black wire coming from the distributor will be connected on the other side and when shifting ,this will send power to the distributor. This will shut of the ignition for a split second and that will enable me to shift into neutral. This is how the system is set up on all the mercruisers. This way , the ESA and the overstroke switch are out of the loop. Another way to work with the ESA is by removing the current one and replacing it with a different type of ESA which is available from CDI.